Pantograph machine movement control assembly

ABSTRACT

Pantograph machine movement control assembly in which relative rotational movement of cutter and work supports about a certain axis is effected in proportion to an X component of movement of a tracing stylus while relative rectilinear movement of the supports is effected in proportion to a Y component of movement of the stylus to cause a cutting portion of a cutter to move through work on the work support in a linear path along a certain line which intersects the certain axis at an acute angle. The assembly is especially advantageous when used for the cutting of letters on the bezel portion of a class ring or the like.

v United States Patent Mechanic [54] PAN TOGRAPH MACHINE MOVEMENT CONTROL ASSEMBLY [72] Inventor: Bernard I. Mechanic, Evanston, Ill.

[73] Assignee: Tiara Corporation, Lincolnwood, Ill.

[22] Filed: May 22, 1970 [21] Appl. No.: 39,642

[ [51] [58] Field of Search ..90/l3.1, 13.6; 33/21 R, 21 B [56] References Cited UNITED STATES PATENTS 1,889,660 11/1932 Homer ..33/22X 1,874,046 8/1932 Jonsson ..33/22 [4 1 May 23, 1972 2,017,843 10/1935 Cuthbert ..33/22 Examiner-Gil Weidenfeld AttorneyAlberts, Brezina & Lund [57] ABSTRACT Pantograph machine movement control assembly in which relative rotational movement of cutter and work supports about a certain axis is efiected in proportion to an X component of movement of a tracing stylus while relative rectilinear movement of the supports is effected in proportion to a Y component of movement of the stylus to cause a cutting 6 Claims, 3 Drawing Figures PATENTEDMM23 IHIZ 3,664,230

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ATTORNEYS PANTOGRAPI-I MACHINE MOVEMENT CONTROL ASSEMBLY This invention relates to a pantograph machine movement control assembly and more particularly to a relatively simple and inexpensive control assembly by which a cutting operation can be readily and quickly set up and performed on a frusto-conically shaped surface such as the bezel portion of a class ring. The assembly may be incorporated in a machine when made or added to an existing machine and is highly accurate in operation while being rugged and reliable.

Although having other applications, the invention is particularly advantageous when used for forming letters on a circular or oval bezel surrounding a stone of a class ring. Such letters may be formed to identify a particular school or university and also to indicate the class year of the student or graduate purchasing the ring. Heretofore, such letters have been cast using lost wax or similar processes which require multiple steps and which are quite expensive.

This invention was evolved with the general object of overcoming the disadvantages of prior art methods and of simplifying and reducing the cost of forming letters on a class ring.

A further object of the invention is to provide a movement control assembly for a pantograph machine which permits cutting operations to be readily and quickly set up and performed on curved surfaces such as generally frusto-conical surfaces.

According to this invention, relative rotational movement of cutter and work supports about a certain axis is effected in proportion to an X component of movement of a tracing stylus in a certain plane while relative rectilinear movement of the supports is effected in proportion to a Y component of movement of the stylus to causea cutting portion of a cutter to move through work on the work support in a linear path along a certain line which intersects the certain axis at an acute angle. With this arrangement, letters, numbers or the like may be set up in one plane for engagement by the tracing stylus and the cutting operation may be performed on a curved or generally frusto-conically shaped surface such as the bezel portion of a class ring. The rings may be of a fixed standard construction and therefore relatively inexpensive and in response to an order from a particular student or graduate, letters signifying his school or university and, if desired, numbers indicating his class year may be quickly set up in a plane for engagement by the tracing stylus and the cutting operation may be. performed with a minimum of time and expense.

According to a specific feature of the invention, first and second intermeshed bevel gears are provided, the first being rotatable about the certain axis and being connected to one of the supports and the second being rotatable about an axis in spaced parallel relation to the line of relative movement of the cutter through the work.

Another specific feature of the invention relates to the construction of the assembly by which it can be either incorporat'ed in a pantograph machine when the machine is made or added to an existing machine.

This invention contemplates other objects, features and advantages which will become more fully apparent from the detailed description taken in conjunction with the accompanying drawings which illustrate a preferred embodiment and in which:

FIG. 1 is a front elevational view of a pantograph machine incorporating a control assembly in accordance with the principles of this invention;

FIG. 2 is an end elevational view on an enlarged scale showing a work support, part of a cutter support and associated structure of the machine; and

FIG. 3 is a sectional view taken substantially along line III III of FIG. 2.

Reference numeral generally designates a pantograph machine incorporating a movement control assembly 11 constructed in accordance with the principles of this invention. The control assembly 1 1 is especially designed for the purpose of engraving letters and numerals or the like on a class ring 12. The class ring 12 has a bezel portion of generally frusto-conical shape on which the letters and numerals are to be formed, a'suitable stone or the like being set within the bezel portion 13.

In the operation of the machine, the ring 12, before mounting of the stone or other setting, is disposed on a support 14 and the threaded shank portion of a thumb screw 15 is inserted through the opening to be occupied by the setting and is threaded into the support 14, a washer 16 being preferably disposed between the head of the thumb screw 15 and the ring. The support 14 is secured to a shaft 17 which is journalled in a housing 18 for rotation about an axis coincident with the axis of the bezel portion 13. The bezel 13 is arranged to be engaged by the pointed cutting end portion 20 of a cutter 21 which is carried by a spindle 22, spindle 22 being journalled for rotation by a spindle housing 23. A pulley 24 on the spindle 22 is arranged to be driven from a motor, not shown, through a suitable belt.

In the operation of the apparatus, letters and numerals are placed on a horizontal planar surface of a work table 26 to be engaged by a tracing stylus 27. When the stylus 27 is moved along the surfaces of letters on the table-26, it has two components of movement, a Y" component to the left or to the right in the plane of the drawing paper and an X component of movement in a direction transverse to the plane of the drawing paper. The shaft 17 and hence the ring 12 are rotated in proportion to the X component of movement of the tracing stylus 27 while the housing 18 is moved relative to the spindle support 23 to the left or the right as viewed in FIGS. 1 or 3, in proportion to the Y component of movement of the tracing stylus 27. In the illustrated arrangement, the spindle support 23 is stationary while the housing'18 is moveable. This arrangement is preferred but the housing 18 could be stationary with the spindle support 23 being movable, if desired. Also,

the spindle support 23 could conceivably be movable about the axis of the bezel portion 13 of the ring 12 with the ring 12 being stationary. The illustrated arrangement, however, is simpler and is therefore preferred.

It isnoted that the axis of the shaft 17 lies at an acute angle to a line in alignment with the path through which the cutting portion moves through the work, so that the letters or numbers are engraved on the generally frusto-conical surface of the bezel 13.

To rotate the shaft 17, a bevel gear 29 is fixed thereon and is meshed with a second bevel gear 30 fixed on one end of shaft 31. A gear 33 is affixed on the opposite end of the shaft 31 and is meshed with a rack 34 which is mounted on the underside of a slide 35. Slide 35 is slidably movable in a housing 36 and has an opening in its upper surface which receives a rod 37. Housing 36 is connected to one end of a sleeve 38 within which the shaft 31 is joumalled and the housing 18 is affixed to the opposite end of the sleeve 38. Sleeve 38 is slidably mounted, for axial movement in an opening 39 in the spindle support 23.

Through conventional mechanism of the pantograph machine 10, the rod 37 has X and Y components of movement respectively parallel and in proportion to the X and Y components of movement of the tracing stylus 27. The Y component of movement is transmitted directly to the housing 18 through the slide 35, housing 36 and sleeve 38. The X component of movement is transmitted to the shaft 17 through the rack 34, gear 33, shaft 31, gear 30 and gear 29.

It is noted that the mechanism for moving the rod 37 may be similar to that illustrated in the Homer US. Pat. No. 1,889,660 issued Nov. 29, 1932 and is such that a cutter may be substituted for the rod 37 and rotated for conventional engraving operations. Also, elements 22-24, 31 and 33-38 may ing assembly 41 is mounted in a member 42 which may be press-fitted into an opening 43 of the housing 18. To mount the housing 18 on the sleeve 38, the housing 18 is formed with an internal cylindrical surface 45 receiving the end portion of the' sleeve 38 and with a shoulder 46 which engages the end of the sleeve 38. A radially extending slot 47 is formed in the housing 18 and the portions thereof on opposite sides of the slot areiarranged to be drawn together by a screw 48 so as to clamp the housing on the end of the sleeve 38.

A spacer sleeve 50 is provided between the bevel gear 30 and the inner ring of a ball bearing assembly 51 and a nut 52 is threaded on the end of the shaft 31 to hold the bevel gear 30 against the end of the spacer sleeve 50. The ball bearing assembly 51 and a second ball bearing assembly 53 journal the shaft 31 in the sleeve 38. Rollers 54 may be provided on the housing 36 for riding on the flat upper surface 55 of a portion of the member 23.

1 claim as my invention:

1. in a movement control assembly for a pantograph machine including cutter and work supports and a control mechanism for controlling movement of said cutter and work supports including a tracing stylus having X and Y components of movement in a certain plane, adaptor means for said control mechanism including rotating means for effecting relative rotational movement of said cutter and work supports about a certain axis in proportion to said X component of movement of said tracing stylus, and rectilinear means for effecting relative rectilinear movement of said cutter and work supports in proportion to said Y component of movement of said tracing stylus to cause a cutting portion of a cutter on said cutter support to move through work on said work support in a linear path along a certain line which intersects said certain axis at an acute angle while said relative rotational movement is being effected. v

2. In an assembly as defined in claim 1, means on said work support for supporting a ring having a bezel portion of generally frusto-conical shape with the axis of said bezel por-'- tion being aligned with said certain axis.

3. In an assembly as defined in claim 1, said rotating means comprising first and second intermeshed bevel gears, said first bevel gear being rotatable about said certain axis and being connected to one of said supports, and said second bevel gear being rotatable about an axis in spaced parallel relation to said certain lineand being connected to said control mechanism to be rotated in proportion to said Y component of movement of said tracing stylus. 1

4. In an assembly as defined in claim 1, said cutter support being stationary and said work support being rotatable about said certain axis and being movable rectilinearly.

5. In an assembly as defined in claim 4, a shafi rotatable about an axis intersected by said certain axis and in spaced parallel relation to said certain line, said shafl being rotated in proportion to said X component of movement, and coupling means coupling said shaft to said work support.

6. In an assembly as defined in claim 5, said rectilinear means including a member joumalling said shafi and movable in a direction along the axis of said shaft in proportion to said Y component of movement of said tracing stylus, and a housing for said coupling means arranged to be secured to said member.

' t i a: a a 

1. In a movement control assembly for a pantograph machine including cutter and work supports and a control mechanism for controlling movement of said cutter and work supports including a tracing stylus having X and Y components of movement in a certain plane, adaptor means for said control mechanism including rotating means for effecting relative rotational movement of said cutter and work supports about a certain axis in proportion to said X component of movement of said tracing stylus, and rectilinear means for effecting relative rectilinear movement of said cutter and work supports in proportion to said Y component of movement of said tracing stylus to cause a cutting portion of a cutter on said cutter support to move through work on said work support in a linear path along a certain line which intersects said certain axis at an acute angle while said relative rotational movement is being effected.
 2. In an assembly as defined in claim 1, means on said work support for supporting a ring having a bezel portion of generally frusto-conical shape with the axis of said bezel portion being aligned with said certain axis.
 3. In an assembly as defined in claim 1, said rotating means comprising first and second intermeshed bevel gears, said first bevel gear being rotatable about said certain axis and being connected to one of said supports, and said second bevel gear being rotatable about an axiS in spaced parallel relation to said certain line and being connected to said control mechanism to be rotated in proportion to said Y component of movement of said tracing stylus.
 4. In an assembly as defined in claim 1, said cutter support being stationary and said work support being rotatable about said certain axis and being movable rectilinearly.
 5. In an assembly as defined in claim 4, a shaft rotatable about an axis intersected by said certain axis and in spaced parallel relation to said certain line, said shaft being rotated in proportion to said X component of movement, and coupling means coupling said shaft to said work support.
 6. In an assembly as defined in claim 5, said rectilinear means including a member journalling said shaft and movable in a direction along the axis of said shaft in proportion to said Y component of movement of said tracing stylus, and a housing for said coupling means arranged to be secured to said member. 